Recently there has been an expanded interest in power conditioning equipment that draws sinusoidal input current from the A.C. line. This need is discussed in the articles by E. Kamm entitled "New Military EMI Specifications Affecting the Input Architecture of A.C. to D.C. Converters", Proceedings of Powercon 8, 1981, and by M. J. Kocher and R. L. Steigerwald entitled "An A.C. to D.C. Converter with High Quality Input Waveforms", IEEE PESC Conference Record, 1982. The present invention provides a digital implementation of a voltage feedback loop and a multiplying digital-to-analog converter in a current feedback loop to provide a power conditioner, which draws sinusoial output current and provides a regulated direct current output voltage and is operable over a wide range of A.C. line frequencies.